The design of antennas in high frequency electronics for mobile communication has been a key factor in the development of ultrafast communication technologies. Modern electronic devices allow users to communicate with other devices using a number of different wireless technologies. The antennas for use with these technologies often require different operational parameters (e.g. input impedance, gain, directivity, signal polarization, resonant frequency, bandwidth and radiation pattern).
The properties of antennas are dependent upon the size, shape and material composition of the antenna elements, the interaction between elements, the relationship between certain antenna physical parameters (e.g. length for a linear antenna and diameter for a loop antenna), and the wavelength of the signal received or transmitted by the antenna. To enable communication using multiple different technologies, some modern electronic devices incorporate separate antennas for each technology, whilst others use a tunable antenna which allows the antenna properties to be modified. Tunable antennas are becoming more and more popular given the increasingly limited space available within the casing of electronic devices.
Tunable antennas are also being used in cognitive radio devices. In order to avoid interference, these devices are required to transmit signals only on frequencies which are not currently being used by other users of the electromagnetic spectrum. Since the available frequencies vary over time, cognitive radio devices must be able to alter the operational parameters of their antennas to satisfy this requirement.
A number of different techniques can be used to modify the operational parameters of a tunable antenna. The apparatus and methods disclosed herein may or may not provide an alternative technique.
The listing or discussion of a prior-published document or any background in this specification should not necessarily be taken as an acknowledgement that the document or background is part of the state of the art or is common general knowledge. One or more aspects/embodiments of the present disclosure may or may not address one or more of the background issues.